Time-restricted feeding shifts the skin circadian clock and alters UVB-induced DNA damage

The epidermis is as a highly regenerative barrier protecting organisms from environmental insults, including ultraviolet radiation, the main cause of skin cancer and skin aging. Here we show that time-restricted feeding (RF) shifts the phase and alters the amplitude of the skin circadian clock and affects the expression of approximately 10% of the skin transcriptome. Furthermore, a strikingly large number of skin-expressed genes are acutely regulated by food intake. While the circadian clock is required for daily rhythms in DNA synthesis in epidermal stem cells, RF-induced shifts in clock phase do not alter the phase of DNA synthesis. However, both the expression of the key DNA repair gene Xpa, and the diurnal sensitivity to UVB-induced DNA damage, are altered by RF. Together our findings indicate an unexpected regulation of skin function by time of feeding and emphasize the important link between circadian rhythm, food intake, and skin health. Overall design: Totally 24 samples were sequenced. One sample for each time point and 8 time points for each feeding group. Each sample was pooled from 2-4 biological replicates.